His remark comes after Cambodian Prime Minister Hun Sen tested positive for Covid-19 and was forced to cancel his participation at the G20 and Apec summits.
Don explained that Hun Sen had been invited as a special guest by the Thai government. The host nation cannot suddenly invite another leader to replace him.
Don was speaking during his visit to the Apec media centre on Tuesday afternoon.
Don also emphasised the significance of Tuesday's Concluding Senior Officials' Meeting, at which Apec senior officials will discuss trade and investment issues in accordance with Apec 2022's theme of “Open. Connect. Balance.”
He assured that Thailand would benefit from this meeting, particularly the Bangkok Bio-Circular-Green (BCG) Goal.
"The outcome of this discussion will provide new impetus to address climate change and current environmental issues. You cannot expect a concrete result in three to five years. What we are discussing now is the preparation for our next generation," Don stated.
The two-day Concluding Senior Officials' Meeting, which will take place on November 15-16 at the Queen Sirikit National Convention Centre, will discuss a multi-year work plan to help drive the region's economic recovery and long-term resilience against future pandemics and other disruptions.